Medical devices, such as electrical stimulators or therapeutic agent delivery devices, may be used in different therapeutic applications, such as deep brain stimulation (DBS), spinal cord stimulation (SCS), pelvic stimulation, gastric stimulation, peripheral nerve stimulation, functional electrical stimulation or delivery of pharmaceutical agents, insulin, pain relieving agents or anti-inflammatory agents to a target tissue site within a patient. A medical device may be configured to deliver therapy to a patient to treat a variety of symptoms or patient conditions such as chronic pain, tremor, Parkinson's disease, other types of movement disorders, seizure disorders (e.g., epilepsy), urinary or fecal incontinence, sexual dysfunction, obesity, mood disorders, gastroparesis or diabetes. In some therapy systems, an electrical stimulator, which may be implantable in some instances, delivers electrical therapy to a target tissue site within a patient with the aid of one or more electrodes, which may be deployed by medical leads, on a housing of the electrical stimulator, or both. In addition to or instead of electrical stimulation therapy, a medical device, which may be implantable in some instances, may deliver a therapeutic agent to a target tissue site within a patient with the aid of one or more fluid delivery elements, such as a pump, a catheter and/or a therapeutic agent eluting patch.